Widely known gaming machines have displays of symbols which form combinations, some of which are designated as winning combinations. For example, traditional slot machines have three to five rotatable reels arranged side by side, which are visible through a glass panel containing a win line. These gaming machines usually employ mechanically spinning physical reels or more recently, video displays of spinning reels. The reels are rotated through a number of angular reel stop positions, and include symbols such as bars or fruit, which are rotated on the peripheral surface of the reels to indicate the reel stop positions. As each reel rotates, its symbols are repetitively displayed in serial order and in visual association with the win line. In other types of video gaming machines, including such games as poker or black jack, the symbols displayed on the video screen may represent playing cards or other items.
In both the mechanical and video type gaming machines, to spin the reels or otherwise initiate game play, a player inserts a token or selects a credit representing a monetary value and then pulls a handle or pushes a button. The token may be coin, currency or the like; credit may be provided by a credit or debit card mechanism. For convenience, all such tokens and credits are referred to herein as simply "coins." The slot machine then randomly stops the spinning reels at selected reel stop positions so that each reel displays a randomly-selected one of its symbols through the glass panel in visual association with the win line. For each reel, the displayed symbol is the reel outcome.
In earlier mechanical or electromechanical gaming machines, the spinning reels were mechanically stopped to determine the reel outcome and sensors detected the reel stop positions to determine whether the player had achieved a winning game outcome. In these traditional machines, the reel both determined and displayed the game outcome.
In more recent developments, a microprocessor or other control circuit randomly determines each reel outcome, and thus the overall game outcome. The microprocessor causes the reels to stop so as to display the selected reel outcomes. In these newer machines, the reel's function is simply to display the reel outcome determined by the microprocessor. In accordance with one known method, each reel stop position is associated with a symbol. The microprocessor then selects one of the reel stop positions, and a reel control mechanism stops the spinning reel to display the symbol at the selected position.
Regardless of how reel outcomes are selected, the combination of displayed symbols is the game result or outcome. Each game outcome corresponds to a payout, a number of which may be zero. Payouts may be associated with game outcomes either mechanically for older machines or electronically, by, for example, using payout tables in memory.
After game outcome is determined, the gaming machine ascertains the corresponding payout, and actuates a coin hopper or the like to dispense the winning payout.
To increase player excitement and interest, some machines dynamically increment payout amounts corresponding to one or more game outcomes. An example of one such technique is provided in U.S. Pat. No. 5,123,649.
Because of the repetitive nature of many gaming machines, there exists a continuing need to develop ever more interesting and exciting games.